So you have a De Vere 504? If the 54 was a predecessor of the 504 (instead of a typo) then I haven't used one. I worked with a bench-mount 504 and Dichromat head for years.
If you have an old and unmaintained machine then the first thing to fix will be the cable tension. The 504 has the head-height and focussing knobs mounted at the front of the baseboard. The drive to the movable parts is via steel cables which are accessible via the rear of the column - the tensioners are obvious.
We didn't have a Varicon head at work, but I have one now at home on a 203 (6x9cm neg stage) and there are no bellows involved - do you mean the focussing bellows for the lens stage? This is one of those moments when a picture would be worth a lot of words... On the 203, three condensers are needed to cover from 35mm to 6x9, with the upper one of the normal two swapped to concentrate the light for the smaller neg - this should be shown in a diagram on the condenser door on the 504 just as it is on the 203, so you will be able to work out what you have and what formats you can cover..
Alignment needs an Allen-key, spanner and screwdriver but is straightforward and very solid once done. I have laser-checked mine every few months but no adjustments have been necessary after the initial set-up.
EDIT: I eventually found a picture of the head on a 54. It is indeed different to the later versions of the Varicon. There does seem to be a diagram of the condenser layout on the front of the head though, so that will be your best reference.
Last edited by MartinP; 11-01-2013 at 03:48 PM. Click to view previous post history.